Be funny.

In one small study, a psychologist asked three men to tell a joke to their friends at a bar while a woman sat at a nearby table. Then those men were instructed to approach the woman and ask for her number. After the man had left, an experimenter approached the woman and asked her to rate the man on attractiveness and intelligence and to indicate how much she would want to date the man long-term.

Results showed that the guys who told jokes were three times as likely to get the woman's number as the men who didn't. They were also rated more attractive and intelligent.

"The effect of a great sense of humor on women's attractions might be partially explained by the fact that funny people are considered to be more social and more intelligent, things that women seek in a mate," anthropologist Gil Greengross writes.

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Surround yourself with friends.

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A 2014 study from the University of California at San Diego found that people were deemed to look better when they were in a group.

In one experiment featured in the study, 25 male and female undergrads looked at 300 photos of women's faces, once in a group photo and once in an isolated portrait. Another experiment repeated the same procedure with 18 undergrads looking at photos of men's faces. Results showed that participants rated both men and women significantly more attractive when they were pictured in a group.

"Having a few wingmen or wingwomen may indeed be a good dating strategy, particularly if their facial features complement and average out one's unattractive idiosyncrasies," study authors Drew Walker and Edward Vul write.

Skip the small talk.

In a 1997 study, State University of New York psychologist Arthur Aron and colleagues separated two groups of undergrads and paired them off, giving each duo 45 minutes to answer a set of questions.

One question set was small talk, and the other was increasingly probing. The people who asked deeper questions felt more connected. One couple even fell in love, an intriguing, though probably insignificant, result.

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Be a leader.

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People may be attracted to power. A 2014 study found that people in a group thought their group's leader was more attractive than did people who weren't in that group.

For the study, researchers recruited 49 Wisconsin legislative aides to rate the attractiveness of different politicians. Sure enough, participants rated the leaders as more attractive if they aligned with their political commitments (Republican or Democrat).

"In contrast with research traditions that treat physical attractiveness as a static trait, our findings highlight the importance of group membership as a lens for perceiving familiar leaders' physical attractiveness," concluded lead author Kevin Kniffin and his colleagues.

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Smile more.

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In two experiments, researchers in Switzerland examined the relationship between attractiveness and smiling.

They found that the stronger the smile, the more attractive a face looked.

In fact, they found, a happy facial expression appeared to compensate for relative unattractiveness.

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Own a dog.

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In a 2014 experiment, 100 Israeli women read vignettes about men. Some of the men were described as "cads": they would cheat on their partner and get into fights. The other men were described as stereotypical "dads": they would work hard at their job and take good care of their kids.

Whenever the story featured a cad who owned a dog, women rated that man as a more suitable long-term partner than a cad who didn't own a dog. Cads with dogs were even rated slightly more attractive than dads with dogs.

The researchers concluded that owning a pet signals that you're nurturing and capable of making long-term commitments. It can also help you appear more relaxed, approachable, and happy.

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Be nice.

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A 2014 Chinese study found that when people hear about how nice somebody is, they find the person's face more attractive.

For the study, 120 men and women looked at 845 photos of other people in their 20s, all displaying neutral expressions. Some of those photos were accompanied by the Chinese words for "decent" and honest"; the others were accompanied by the Chinese words for "evil" and "mean"; still others weren't accompanied by any information.

Participants ended up rating people more attractive when they were described as nice than when they were described as mean or when there was no additional information about them.

Live in a high-status place.

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In a small Cardiff Metropolitan University study in which a man was photographed with a casual posture in a "high-status" luxury apartment and a "neutral-status" standard apartment context, the high-status men received higher attractiveness rating from a group of 35 female undergrads.

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Play good music.

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In a 2014 study, researchers asked about 1,500 women (whose average age was 28) to listen to simple and complex pieces of music and rate the attractiveness of the composer.

The results showed that women preferred the more complex music, and said they would choose the composer of the more complex music as a long-term partner.

Date someone pleasant.

Researchers have long been aware of a phenomenon they call "mate-choice copying," which describes what happens when women like other women's boyfriends.

A 2012 study suggests that women only like the object of someone else's affection if that someone else is kind.

Forty female participants looked at groups of three images in which a photo of a woman was sandwiched in between two photos of men. The woman was captured in profile, so that she appeared to be looking at one of the men. Sometimes she was smiling; sometimes she was wearing a neutral expression. Sometimes she had been described as pleasant; sometimes she had been described as unpleasant.

When the women were asked which man they found more attractive, they tended to choose the man who was being "looked at" by a smiling, pleasant woman.

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Cultivate mindfulness.

Australian researchers recently studied undergrads participating in a speed-dating session, and found that mindful men tended to receive higher attractiveness ratings from women.

Before the session began, 91 students were asked to fill out a mindfulness questionnaire, in which they indicated how much they agreed with statements like, "I perceive my feelings and emotions without having to react to them."

After each interaction with an opposite-sex partner, students privately indicated how "sexy" they found their partner and how much they'd like to date that person.

Results showed that men were generally more drawn to physically attractive women. (Independent coders had rated the students' attractiveness beforehand.) But women were generally more attracted to mindful men.

The researchers suggest that mindful men may have been more attentive to partners during the brief interactions and may have done a better job at regulating their anxiety, which in turn made them more attractive.

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Play extreme sports (carefully).

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A 2014 study led by researchers at the University of Alaska at Anchorage found that women are attracted to men who take what the researchers call "hunter-gatherer risks."

Two hundred and thirty-three undergrads filled out questionnaires about how attractive they would find a partner who engaged in certain risky behaviors.

Hunter-gatherer risks included mountain biking, deep-sea scuba diving, and extreme rollerblading. "Modern" risks included plagiarizing an academic paper, casually handling chemicals in a lab, and not updating the virus-protection software on your computer.

Results showed that women said they would be more attracted to men who engaged in hunter-gatherer risks — the kinds that were similar to risks faced by ancestral humans. Women said they would be less attracted to men who engaged in modern risks, which might seem just plain dumb.

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Wear red.

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University of Rochester researchers found that women who wear red may be more attractive to men.

The study featured a series of experiments, in which groups of about 30 male undergrads looked at black-and-white headshots of a young woman standing against either a red, white, gray, green, or blue background.

Results showed that the men perceived women standing in front of a red background as more attractive and more sexually attractive, and were more likely to want to date them.

Interestingly, when men were asked to indicate what factored into their attractiveness rating, few mentioned the background color, suggesting that the preference for red is subconscious.